Electric lamp or similar device and method of manufacture



A. GREINER Feb. 20, 1940.

ELECTRIC LAMP 0R SIMILAR DEVICE AND IETHOD 0F IANUFACTURE Filed Apri1'30, 1937 2 Sheet s-Sheet 1 Inventor: V Alfrsd Greinen.

Attorney.

A. GREINER Feb. 20, 1940.

ELECTRIC LAMP 0R SIMILAR DEVICE AND METHOD OF MANUFACTURE Filed April 30, 1937 2 Sheets-Sheet 2 Fig :4.

Inventor. Alfi-ed Greinerx y Hi Attorney.

Patented Feb. 2.0, 1940 ELECTRIC LAMP OB SIMILAR. AND METHOD OF MANUFACTURE Alfred Greiner, Cleveland Heights, Ohio, aoslgnor to General Electric Company, a corporation of N ew York Application April 8., 1937, Serial No. 189,012

lOClalm's.

My invention relates to electric lamps or simllar devices comprising a bulb or envelope having an electric energy translation element sealed therein and to methods of manufacturing the same. More particularly, my invention relates to electric incandescent lamps 'of the miniature type comprising an electric energy translation element sealed in a glass envelope. Although not limited thereto, my invention is particularly adapted to devices having terminal contact members at different portions thereof, an example of which is the double-ended lamp, the terminal contact members of which are located at opposite ends. The lamp comprising my invention is particularly adapted for use in strings for various decorative purposes such as Christmas tree ornamentation, although .lt may be used for other purposes, such as automobile, dome or dash lighting.

According to my invention, the lamp bulb is provided with a neck portion to which a metallic thimble or endcontact member is sealed. The filament is electrically connected to said thimble and is supported thereby. The bulb is preferably evacuated through a, small orifice or aperture in the thimble, and the latter subjected to heat to thereby melt a small q antity of glass, solder or other fusible material disposed adiacent said orifice, which material th 1n fiows into and closes the evacuation orifice to thereby hermetically seal the bulb.

In the manufacture of electric miniature lamps of the butt-sealed type a considerable number of parts are necessary, as well as operations, such as basing and exhaust tubulation. It is accordingly one of the objects of my invention to provide an electric miniature lamp simple in construction and consisting of a minimum number of parts. A further object of my invention is the provision of an electric miniature lamp which can be easily and economicallymade, and which requires a minimum number of operations in the manufacture 'of the same. A still further object of my invention, is toprovide a method .for the manufacture of electric miniature lamps which method eliminates the customary basing and exhaust tubulationoperations heretofore required in the manufacture of lamps of the butt-sealed type.

'Othercb cats and advantages of the invention will appeanfrom the following detailed descript'on of species thereof and from the accompanying drawings, in which:

' Figs. 1 to 4 are sectional views illustrating the successive steps involved inthe manufacture of a lamp according to one form of the invention;

(Cl. 170-29) I Fig. 5 is an elevation of the lamp shown in Fig. 4; Figs. 6 and 7 are sectional views of modified forms of thimble construction adapted for use in the lamp shown in Fig. 4; Figs. 8 to 11 are sectional views illustrating the successive steps involved in 5 the manufacture of a lamp according to another form of the invention; Fig. 12 is a perspective view of a modified form of end contact member or thimble construction adapted for use in the lamps shown in Figs. 4 and 11: Figs. 13 to 15 are 10 sectional views illustrating the successive steps involved in the manufacture of a lamp according to still another form of the invention; and Fig.

16 is a view illustrating one form of apparatus suitable for simultaneously evacuatin and seal- 15 log the orifice of a lamp constructed inaccordance with my invention.

Referring to Figs. 1 to 4, illustrating one form of my invention, the lamp there shown comprises a filament mount I! (Fig. 2) sealed within a 20 glass bulb ii. The filament mount ill comprises a pair of cylindrical end contact members or metallic thimbles l2, it, the open ends of which face each other and to-which filament support wires I, ll are spot welded. The ends of a filament II are fastened to the support wires it, It. The thimbles l2, I! are preferably made ofchrome iron or some other suitable metal having a coefficient of expansion approximating that of the glass used for the bulb ll. Thimble i8 is provided with a small orifice or aperture il in the end wall It thereof, through which evacuation of the bulbis effected. .-It will be noted that the support wire it; whleh'is spot welded-to thimble II, is formed with a bent portion it for the 'puras pose of positioning the weld at the side of and a slight distance awayfrom the orifice ll, thereby insuring the maintenance of such opening.

-In assembling the filament mount and bulb, a small quantity. of solder, soft melting glass, wax 40 or othensimilar. fusible material it which, when heated, will soften and flow, is first placed within thethimble it closely adjacent the orifice-ll therein. Although I have shownthe fusible material Il'in the-form of a bend of glass loosely disposed within the thimble ll. it should .be understood that such material may be of any other suitable shape or form,- such searin and may be disposed on the outside of the thimble it closely adjacent theorifiee H as well as on the inside thereof. The fusible material having been placed on or within the thimble ll, the.entire filament mount II isthen inserted in the bulb ll through one of the cylindrical open ends or neck portions 2|, ll of the same. The inside diameters of the neck portions 2|, II are made slightly larger than the outside diameter-of the thimbles If, It, thus permitting the latter to slide freely therethrough. After the filament mount has been centered 01'' positioned within the bulb so that the neck portions 2|, 2| overlap the thimbles II, II approximately the same amount. both thimbles are fused or sealed to the bulb by the application of heat to the bulb neck portions ii, 2|. Pressure may also be applied to the plastic glass to press it firmly against the metal and assure a tight seal therebetween. The lamp is then ready for evacuation, which is preferably can-fell out in a mum chamber, although the same may be effected in any other known manner. After obtaining the necessary vacuum within the bulb, the apertured thimble I 3 provided with the fusible material 26 is heated with an induction heater or in any other suitable manner, thereby melting the fusible material which then flows into the orifice or aperture ll, closing the same and hermetically sealing the lamp. The finished lamp produced by the above-described method, and shown in elevation in Fig. 5, can thus be made in a simple and economical manner, requiring a minimum number of manufacturing operations.

Figs. 6 and 7 illustrate alternate methods of disposing the fusible material 20 on or within the thimble fl and closely adjacent the orifice l'l therein. In Fig. 6 the fusible material 26' is in the form of a ring 22 disposed within the thimble II and provided with an opening corresponding to the orifice II in the thimble. The ring of material 22 is adapted to seat on the end wall ll of the thimble. and is preferably fastened securely to such thimble by fusion or in some other way. In Fig. 7 the fusible material 20 is disposed on the outside of the thimble I I, and is likewise in the form of a ring 2! having an opening corresponding to the orifice ll. The end wall ll of the thimble, in this instance, is depressed to form a seat It adapted to receive the ring 23 of fusible material, which is securely fastened to such seat by fusion or other means.

In Figs. 8 to 11 I have illustrated a diiferent method of manufacturing a lamp comprising my invention. In this instance, the filament mount 2! (Fig. 8) is similar to the mount I I except for the thimble II which; in this case, is first sealed by itself to one of the neck portions II of the bulb. Instead of the thimble it being attached to support wire II, a bead of solder or other current-conveying fusible material 26 is securely fastened to the end thereof. The filament mount 2! is inserted within the bulb it through the open end 21 thereof and positioned therein so that the bead of solder 26 is disposed in close proximity to the orifice I! in thimble IS. with the mount II in this position, the thimble I2 is then fused or sealed to the surrounding bulb neck portion Ii by the application of heat thereto. The bulb is then evacuated and the thimble ll subjected to heat in the same manner as described in connection with Figs. 1 to 4. This heat causes the bead of solder II to melt and fiow into the orifice ll. thereby closing the same and hermetically sealing the lamp. At the same time, the solder or other current-conveying material it establishes the electrical connection between the thimble II and the lead wire II and associated filament mount II.

A modified form of thimble constructionis illustrated in Fig. 12, in which a filament supporting tongue II extends from t P end rectly fastened, thereby dispensing with the filament support wires I4 and II. This particular form of thimble may be" used in either of the lamps shown in Figs. 4 and 11.

In Figs. 18 to 15, I have illustrated still another method of manufacturing a lamp according to my invention. In this form of lamp the thimbles l2, I! are inverted so that their open ends extend outwardly of the lamp instead of inwardly, as in the previous forms. The filament mount 30, in this modification, comprises a pair of thimbles I 2, I2 and a filament l6 extending therebetween and connected to said thimbles by support wires H, H spot-welded to the end walls II, II of the thimbles. The filament mount 36 is inserted within the bulb ll through one of the open ends thereof, and centered within the same. In this position, one of the thimbles I2 is fused or sealed to the surrounding bulb neck portion II by the application of heat to such neck portion. The lamp is then evacuated at 2 the opposite end through the small clearance space provided between the cylindrical walls of the unsealed thimble l2 and the surrounding bulb neck portion 2|. Although I prefer to exhaust the lamp in a vacuum chamber, the evacuation 80 may be accomplished, if desired, through an exhaust tube 3| extending from that end of the bulb as yet not sealed to a thimble. This exhaust tube is preferably provided on the bulb by simply leaving a sufilcient length of the original glass tube from which the bulb was blown. Evacuation of the bulb having been completed by either of the above methods, the bulb neck portion 2| and associated thimble I! as yet unsealed,

and between which evacuation has taken place, 40

are fused or sealed together by the application of heat to said neck portion 2 l, thereby hermetically sealing the lamp and completing the same.

In the event an exhaust tube 3| has been employed for evacuation purposes, the same is cut or cracked off at the outer end of the associated thimble.

Referring to Fig. 16, I have there illustrated a form of vacuum chamber suitable for carrying out the evacuation and orifice-sealing operations 80 referred to above in connection with the lamps shown in Figs. 4 and 11. The evacuating device comprises a housing 32, which may be made of glass, and a base 83 on which the housing is adapted to seat to form a vacuum-tight joint 34 so therebetween. The base I! is formed with an exhaust tube ll opening into the housing 32, and is further provided with relatively heavy current-supplying leads 36, 36. A lamp-supporting mounting 31 extends between said leads and so is forined with a heating coil 86 adapted to receive one of the thimbles of-a lamp. The upper extremity of one of said leads 8. is provided with a supplementary lamp supporting bracket 39 adapted to fit over the upper end of the lamp or to be exhausted, and insulated from the metallic thimble at such upper end. The unsealed or exhaust end of a lamp of the type shown in Figs. 4 and 11 having been inserted within the heater coil 36, and the supplementary bracket it placed over the upper end-=of the lamp, the housing 32 is then placed over the lamp and positioned on its seat on the base 83 to form a vacuum-tight Joint 84 therebetween. The chamber within the housing is then exhausted through the exhaust s tube 8!. After the required vacuum has been obtained within the chamber, an electric current is passed-through the leads 8., I. to thereby energize the heating coil 8|. The heat exerted by said coil on the enclosed metallic thimble of the lamp melts the small mass of fusible material disposed therein, which material then fiows into the small evacuating orifice in the end wall of such thimble, thereby closing the same and hermetically sealing the lamp.

What I claim as new and desire to secure by Letters Patent of the United States is.

1. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions, a pair of tubular thimble-shaped metallic end contact members fused along their sides directly to the walls of the end portions of said envelope and forming part of the envelope, and a filament united at its ends to said end contact members and supported solely thereby.

2. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions, a pair of tubular thimble-shaped metallic and contact members fused along their sides directly to the walls of the endportions of said envelope and forming part of the envelope, one of said members being provided with an aperture in the end wall thereof, a filament united at its ends to said end contact members and supported solely thereby, and a quantity of fusible material disposed within said aperture to thereby close the same and hermetically seal said envelope.

3. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions, a pair of tubular thimble-shaped metallic end contact members fused along their sides directly to the walls of the end portions of said envelope and forming part of the envelope, one of said members being provided with an aperture in the end wall thereof, lead wires united to said end contact members, a filament fastened at its ends to said lead wires and supported solely thereby. and a quantity of fusible material disposed within said aperture to thereby close the same and hermetically seal said envelope.

4. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions, 9. pair of tubular thimblershaped metallic end contact members fused along their sides directly to the walls of the end portions of said envelope and forming part of the envelope, one of said members being provided with an aperture in the end wall thereof, lead wires electrically connected to said end contact member, a filament fastened at its ends to said lead wires and supported solely thereby, and a quantity of fusible material electrically connecting one of said lead wires to the apertured end contact member and closing said aperture to thereby seal said envelope.

5. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions. a pair of open-ended tubular metallic thimblesfused along their sides directly to the walls 01 the end portions of said envelope with their open .ends extending inwardly of the same and forming part of the envelope, and a filament united at its ends to said thimbles and supported solely thereby.

6. A miniature electric lamp comprising a double-ended glass envelope having tubular end portions, a pair of open-ended tubular metallic thimbles fused along their sides directly to the walls of the end portions of said envelope with their open ends extending outwardly of the same and forming part of the envelope, and a filament united at its ends to said thimbles and supported solely thereby.

7. A miniature electric lamp comprising a double-endedglass envelope, a pair of open-ended metallic thimbles sealed directly to the ends of said envelope with their open ends extending inwardly of the same, one of said thimbles being provided with an aperture in the end wall thereof, a filament fastened at its ends to said thimbles and supported solely thereby, and a quantity of fusible material disposed within said aperture to thereby close the same and hermetically seal said envelope.

8. A miniature electric lamp comprising a double-ended glass envelope, a pair of open-ended metallic thimbles sealed directly to the ends of said envelope with their open ends extending inwardly of the same, one of said thimbles being provided with an aperture in the end wall thereof, lead wires electrically connected to said thimbles, a filament fastened at its ends to said lead wires and supported solely thereby, and a quantity of fusible material electrically connecting one of said lead wires to the apertured thimble and closing said aperture to thereby seal said envelope.

9. The method of manufacturing electrical devices which consists in forming a filament mount by uniting the opposite ends of a filament to metal thimbles, one of which is provided with an orifice and a quantity of fusible material adjacent said orifice, inserting said filament mount within a container having opposed openings therein by drawing said mount longitudinally through one of said openings until said thimbles are located one adjacent each of said openings. fusing said container to said thimbles, exhausting said container through said orifice, and applying heat to said fusible material to cause the same to fiow into and hermetically seal said orifice.

10. The method of manufacturing electrical devices which consists in forming a filament mount by uniting the opposite ends of a filament to metal thimbles, inserting said mount into a doubleended container by drawing it longitudinally through one'oi' the open ends thereof until said "thimbles are located one adjacent each of said open ends of the container, sealing one end of said container to one of said thimbles, exhausting said container through the other unsealed end thereof around the other thimble, and fusing the said unsealed end of said container to the said other thimble.

AIJ'RKDGREINER.

CERTIFICATE OF CORRECTION. Patent No. 2, 191,5h6. February 20, 191p.

ALFRED GREI-NER.

It ia-hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 first column, li e 2h, claim 2, for tire word "and" read endfand that the said Lettera Patent should be read with this correction therein that the same may conform to the record 01 the case in the Patent Office.

Signed and sealed this 2nd day of April, A. D. 1910;

Henry Van Arsdale,- (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION. Patent No. 2,191, u6. February 20, 191p.

v. ALFRED GREI-NER. It'isherebycertified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 first column, 11 2h, claim 2, for the word "end" read end; and that the said Letters. Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of April, A. D. 191$).

Henry Van Arsdale,-

( Acting Commissioner of Patents. 

